Refers to a person who follows a leader, ideology, or trend, often with a nuance of lacking originality or blindly copying.
He is known as a follower of the charismatic business leader.
Imitators of the new product quickly appeared.
模倣者 explicitly means 'imitator' and focuses on copying behavior, whereas 追随者 can also mean a loyal follower without necessarily copying.
Compound of 追随 (ついずい, 'following') + 者 (しゃ, 'person'). The exact historical derivation is uncertain, but the word follows a common Sino-Japanese pattern for agent nouns.